Unilateral primary aldosteronism as an independent risk factor for vertebral fracture.

CONTEXT: Primary aldosteronism (PA) is known to increase vertebral fracture (VF), although the detailed mechanism remains to be elucidated. We hypothesized that the PA subtype is associated with VF.

OBJECTIVE

To evaluate whether unilateral PA is associated with the prevalence of VF.

DESIGN

This was a retrospective cross-sectional study in a single referral centre.

PATIENTS: We identified 210 hypertensive patients whose clinical data were available for case-detection results. One hundred and fifty-two patients were diagnosed with PA using captopril challenge tests.

MEASUREMENTS: We measured the prevalence of VF, according to PA subtype.

RESULTS

One hundred thirteen patients with PA were subtype classified by adrenal vein sampling. Of these, 37 patients had unilateral PA, 76 patients had bilateral PA, 58 patients had non-PA; 39 patients with PA were not subtype-classified. Patients with PA had a higher prevalence of VF (29%, 44/152) than those with non-PA (12%, 7/58; P = .011). Moreover, unilateral PA had a higher prevalence of VF (46%, 17/37) than bilateral PA (20%, 15/76; P = .021). There was no significant difference in the prevalence of VF between bilateral PA and non-PA. Unilateral PA was an independent risk factor for VF after adjusting for age and sex (OR: 3.16, 95% confidence interval: 1.12-8.92; P = .017). Among patients with unilateral PA, serum cortisol concentrations after 1-mg dexamethasone suppression test were higher in those with VF (1.32 ± 0.67 g/dL) than those without (0.96 ± 0.33 g/dL; P = .048).

CONCLUSIONS

Unilateral PA is an independent risk factor for VF.